Fedline or other complex file structure import

I'm wondering if anyone out there has built an import for consuming Fedline files (incoming/outgoing domestic and international funds transfers)? 

It's a complex file format involving tags and unstructured delimited sections. I was going good splitting by custom delimiters until I hit a row with an extra tag (so I would want to shift everything else right by a couple columns).  

I'm new-ish to M, so if anyone can point to a solution to a similar file import, it would be appreciated.